Flame Ionization Detector - FID sensing measures hydrocarbons down to ultra-trace levels

Flammable hydrocarbon samples can be measured at very low levels with our Flame Ionization Detector (FID) sensors. Based around the detection of ions formed by combustion, they are key to the sensitive, accurate measurements delivered by our SERVOPRO Chroma, FID and HFID analyzers.

FID sensors are designed to measure flammable Total Hydrocarbons (THC) down to parts-per-billion (ppb) levels.

They work by detecting ions formed in the combustion of organic compounds in a sample, producing charged molecules that cause electrical conduction between two electrodes.

The ions are attracted to a collector plate and induce a current upon hitting the plate. The FID measures this conduction and produces an output which is directly proportional to the concentration of THC in the sample.

This signal is then enhanced by a logarithmic amplifier that reduces drift and thermal noise, delivering an accurate, nondepleting measurement with 100ppb resolution.

Related and alternative technologies

FID can be used with Gas Chromatography techniques to provide trace gas measurements for a wide range of applications. Some carbon-containing compounds, and a number of gases of common industrial interest, fail to significantly ionize in a flame and so are either undetectable or may not be effectively measured by the FID.

Key applications

Air separation units

Product pipelines

Cylinder filling stations

Key benefits

Decreased drift and thermal noise

Accurate, non-depleting measurement

Resolution of 100ppb

Ideal for

Industrial processes where THC contamination is possible, such as air separation units, product pipelines, and cylinder filling stations.

Explore the FID analyzers we have for your process

Learn more about all our gas analyzer solutions that use this sensor technology.

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The Chroma is optimized to specific background gases to ensure optimum performance for your application.

  • Versatile, ultra-accurate trace gas analysis
  • Choice of non-depleting sensor technologies
  • Cost-effective solution for process control or quality monitoring
  • Works in a wide range of background gases
  • Compact 4U rack-compatible design
  • Flexible communication options



With trace analysis capability, the FID is ideal for ASU safety and quality control applications.

  • Ideal for ASU safety and quality control
  • Robust Flame Ionization Detector analysis
  • Delivers trace Total Hydrocarbon measurements
  • An adaptable solution for diverse applications
  • Low-noise FID sensing for superior accuracy
  • Range of remote communication options



Utilizes an internally heated oven set to 190°C (374°F) to maintain the sample gas above its dew point, for optimum performance in total hydrocarbon analysis (THC).

  • Highly sensitive trace hydrocarbon analyser
  • Ideal for vehicle/engine certification testing
  • Heated FID for volatile hydrocarbon concentrations
  • Delivers real-time, on-stream gas analysis
  • Cutter system removes non-methane hydrocarbons
  • Four user-definable measurement range options

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Need more advice? Contact the gas analysis experts today

If you still need guidance to find the best solution for your process, we’re here to help. Our expert team combines applications knowledge with extensive experience and deep understanding of the sensing technologies available. We’ll help you find the solution that meets your unique needs.

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